ROAS means return on ad spend. It is the revenue your ads generated divided by what you spent on those ads. Spend $2,500 and make $10,000 in sales, and your ROAS is 4. That is usually written as 4:1, or 400%, or “$4 back for every $1 in”.
The formula takes five seconds. Reading the result correctly is the hard part, and it is where most advertisers lose money.
Here is the reason. ROAS counts revenue, not profit. It has no idea what your product costs to make or ship. A 4x ROAS can be a solid win or a real loss depending entirely on your margin, and the number itself will never tell you which.
What is the ROAS formula?
ROAS = revenue from ads / ad spend
That is it. Both numbers have to cover the same time window and the same campaigns, or the answer is meaningless.
Three worked examples at different scales:
Example 1. A small store. Ad spend $2,500. Revenue attributed to ads $10,000. ROAS = 10,000 / 2,500 = 4.0. Written as 4:1 or 400%.
Example 2. A bigger account. Ad spend $16,000. Revenue $48,000. ROAS = 48,000 / 16,000 = 3.0. Three dollars back per dollar spent.
Example 3. An account in trouble. Ad spend $2,500. Revenue $1,750. ROAS = 1,750 / 2,500 = 0.7. You got 70 cents back for every dollar. Anything under 1.0 means the ads did not even return the cash you put in, before you paid for the product.
How do you read a ROAS number?
The same result gets written three ways, and people mix them up constantly.
| Way it is written | What it looks like | What it means |
|---|---|---|
| As a ratio | 4:1 | $4 of revenue per $1 of ad spend |
| As a multiple | 4x or 4.0 | The same thing |
| As a percentage | 400% | The same thing again |
What this means for you: 4:1, 4x and 400% are identical. Google Ads reports ROAS as a percentage in the interface, so a target ROAS of 400% in your bid strategy is a 4x target. If someone tells you they hit “400% ROAS”, they did not quadruple your profit. They made four dollars of revenue per dollar spent, which might be a loss.
Watch for one more trap. Some people say “ROAS of 40%” when they mean ad spend was 40% of revenue. That is the inverse, sometimes called ACOS or cost of sale, and it works out to a 2.5x ROAS. Always ask which direction the number runs.
What is a good ROAS?
There is no universal good ROAS, and any benchmark that gives you one is guessing. The honest answer is that a good ROAS is anything comfortably above your break even ROAS, and your break even ROAS depends on your gross margin.
You calculate it like this: break even ROAS = 1 / gross margin.
At a 50% margin, break even is 1 / 0.50 = 2.0. At a 25% margin it is 1 / 0.25 = 4.0. So a 4x ROAS is double your break even in the first business and exactly break even in the second. Same number, two completely different outcomes. We go through this in detail in our guide to break even ROAS.
Why can a 4x ROAS still lose money?
Because ROAS uses revenue, and revenue is not yours to keep. Product cost, shipping, payment fees and returns all come out first.
Here is the same 4x ROAS across different gross margins. In every row the business spent $10,000 on ads and made $40,000 in revenue.
| Gross margin | Gross profit on $40,000 | Minus $10,000 ad spend | Result at 4x ROAS |
|---|---|---|---|
| 20% | $8,000 | $8,000 – $10,000 | Loses $2,000 |
| 25% | $10,000 | $10,000 – $10,000 | Exactly break even |
| 30% | $12,000 | $12,000 – $10,000 | Makes $2,000 |
| 40% | $16,000 | $16,000 – $10,000 | Makes $6,000 |
| 50% | $20,000 | $20,000 – $10,000 | Makes $10,000 |
| 70% | $28,000 | $28,000 – $10,000 | Makes $18,000 |
What this means for you: a 4x ROAS is a $2,000 loss for a low margin retailer and an $18,000 win for a software or service business. Before you judge any ROAS number, work out your gross margin. Nothing else in this post matters more.
And these figures are still generous, because none of them subtract overheads, salaries, software or agency fees. The $2,000 row at a 30% margin has to cover all of that before anyone gets paid.
What is the difference between ROAS, ROI and POAS?
They answer three different questions. Using the wrong one is how accounts look healthy right up until the accounts arrive.
| Metric | Formula | What it tells you |
|---|---|---|
| ROAS | Revenue / ad spend | How much revenue the ads produced. Ignores costs. |
| POAS | Gross profit / ad spend | How much actual profit the ads produced. |
| ROI | (Gross profit – ad spend) / ad spend | The percentage gain on the money you put in. |
Run the same numbers through all three. Ad spend $10,000, revenue $40,000, gross margin 40%.
- ROAS = $40,000 / $10,000 = 4.0
- Gross profit = $40,000 x 0.40 = $16,000
- POAS = $16,000 / $10,000 = 1.6
- ROI = ($16,000 – $10,000) / $10,000 = 60%
What this means for you: the headline “4x” is really a 1.6x on profit and a 60% return. All three are correct. Only two of them are useful. POAS is the one to steer by if your product margins vary a lot between items, because a 4x ROAS made of low margin bestsellers is worth much less than a 4x made of high margin products.
How do you actually track ROAS correctly?
ROAS is only as good as the revenue number feeding it, and that number is wrong in a surprising share of accounts.
Three things to check before you trust the figure:
- Conversion value has to be passed dynamically. If your tag sends a fixed value for every purchase, your ROAS is fiction. Google explains value tracking in its conversion tracking documentation.
- Count each sale once. Duplicate purchase tags across GA4, the platform pixel and your cart are the most common cause of an implausibly good ROAS.
- Subtract returns and discounts. If 12% of orders come back, your reported ROAS is roughly 12% higher than reality.
Our post on Google Ads conversion tracking covers the setup and the failures we see most often. If tracking is broken, every other decision in this post is built on sand.
One more honest note. Platforms report their own attributed revenue, and Google and Meta will both claim the same sale. Adding up platform ROAS across channels will always overstate your business. Compare platform revenue against your actual store revenue every month and expect a gap.
Common questions
What does 4:1 ROAS mean?
It means you made $4 in revenue for every $1 you spent on ads. It is the same as 4x or 400%. Whether it is profitable depends on your gross margin. At a 25% margin, 4:1 is exactly break even.
How do you calculate ROAS?
Divide the revenue attributed to your ads by the amount you spent on those ads over the same period. $12,000 in revenue from $3,000 of spend is a ROAS of 4.0. Use gross profit instead of revenue and you get POAS, which is the more useful number.
What is a good ROAS for eCommerce?
It depends on your margin, not on an industry benchmark. Work out break even ROAS as 1 divided by your gross margin, then aim above it. A store at a 40% margin breaks even at 2.5, so 3.5 to 4 is a healthy target. A store at a 20% margin breaks even at 5.0 and needs far more.
Is ROAS the same as ROI?
No. ROAS measures revenue against ad spend and ignores costs. ROI measures profit against the money invested. A 4x ROAS at a 40% gross margin works out to a 60% ROI, which is a much less exciting number and a much more honest one.
Why is my ROAS dropping as I increase budget?
This is normal and expected. The cheapest, highest intent demand gets bought first. As you spend more you reach people further from a purchase, so efficiency falls. The question is not how to hold ROAS flat, it is whether the extra volume is still above your break even.
Should I use target ROAS bidding?
Only once you have reliable conversion value tracking and enough conversion volume for the algorithm to learn from. Setting a target ROAS on thin or wrong data usually chokes delivery. Google outlines the requirements in its Smart Bidding documentation.
Not sure whether your ROAS is actually profitable?
Most stores we look at are steering by a ROAS number that either double counts revenue or ignores margin. Both feel fine until you compare the ad platform against your actual books. Our eCommerce advertising team can check your tracking, work out your true break even, and set a target that protects profit instead of chasing a headline multiple.
If you sell through Shopping or Performance Max, start with our Google Shopping ads guide. If you generate leads rather than sales, cost per lead benchmarks is the better starting point. Or just get in touch and we will look at your numbers with you.
